Slack separation apparatus and method

Abstract

A hopper, method and system for separating slack from a mixture of product and slack (S) is disclosed. The hopper comprises a first gate (12a) movable between respective open and closed positions, and a slack remover (20) arranged such that when the first gate is in its closed position, the first gate and the slack remover define a first product receiving volume therebetween, the slack remover having a first internal chamber for receiving slack and a first filter wall separating the first internal chamber from the first product receiving volume, the first filter wall being configured to prevent the passage of product but allow the passage of slack. The first gate provides a first path for product to exit the first product receiving volume when the first gate is in its open position, and when the first gate is in its closed position, the first path is closed and the product is retained within the first product receiving volume, and the slack remover is configured to remain substantially stationary as the first gate is moved between its open and closed positions.

Description

[Technical field]

[0001] The present disclosure relates to an apparatus, system and method for separating excess slack from a product and slack mixture, for example slack being food coatings such as sugar in confectionery, crumbs in breaded products, seasonings in snack foods, starch flour, etc.

[0002] More particularly, aspects of the invention relate to improved hopper designs and systems and methods that use said hoppers. The apparatus and methods according to the present invention are particularly suited for use in the food packaging industry. [Background technology]

[0003] Some products are packaged with additional materials, referred to herein as slack. Slack, which is generally in a substantially solid or liquid state, may be mixed with a solid product before the mixture is dispensed into packages. When the slack is substantially solid, its dimensions are significantly smaller than the dimensions of the product itself; often, the slack is at least 1 / 5 and more commonly at least an order of magnitude smaller (i.e., less than 1 / 10) than the dimensions of the product. For example, the slack may be in the form of a powder or particulates.

[0004] For example, slack may be included in a product package to protect the product from deterioration due to exposure to certain chemicals or due to movement of the product within the package. Alternatively or additionally, slack may be included to enhance the product in some way. For example, a food product may be provided with a light coating of sugar, crumbs, or herbs to improve taste, texture, and / or appearance. Alternatively or additionally, fragile products such as potato chips and crisps may crumble or break and form slack in the form of crumbs.

[0005] Additionally, some processes (eg, coating processes) may require a higher percentage of slack to be mixed into the product than is desired in the final packaged product, for example to ensure a uniform coating.

[0006] Excess slack causes many problems in food manufacturing and in the final packaged product.

[0007] For example, in many products it is undesirable to have excess slack floating freely within the package - for example, if excess crumbs float in the packaging of an ovenable breaded food product, the excess slack could burn on the oven tray.

[0008] Additionally, problems can also occur when a mixture of product and slack falls into a package and is sealed at the top, as happens in vertical form-fill-seal machines (also known as VFFS machines). If the slack falls slower than the product, for example if the product is a jelly and the slack is a sugar coating, the slack (sugar) can become trapped in the seal and impair the quality of the seal. To reduce the occurrence of this problem, the sealing process can be delayed to allow the slack to settle before sealing, but this method slows down the process and reduces the output of packaged product.

[0009] Excess slack can also accumulate or stick to product handling machinery, potentially resulting in clogged machinery and high maintenance costs. This is particularly problematic for slack that is commonly found in food products, such as sugar, starch, and fatty crumbs. Similarly, the machinery that handles the products produces the food, and slack that remains in the machinery for extended periods can spoil or attract pests, compromising public health.

[0010] Therefore, it is desirable to separate the excess slack from the product prior to packaging.

[0011] Existing devices and systems for removing slack tend to be complex to design and manufacture, require large energy inputs, and / or are capable of removing only a relatively low percentage of the slack that travels with the product along the product path (i.e., the continuous product flow or the path along which successive portions of the product travel).

[0012] Therefore, there is a need for alternative methods and / or apparatus for separating excess slack from a product, which preferably contribute to solving one or more of the problems discussed above. Summary of the Invention

[0013] The claimed invention provides improved apparatus, systems and methods for removing slack from products. Specifically, the apparatus and systems according to the invention include hoppers used to store, measure and discharge products with reduced slack levels. For example, when used in the food industry, the claimed invention is suitable for, but not limited to, separating loose sugar from confectionery and separating excess condiments and crumbs from crisps and chips. These apparatus, systems and methods are capable of removing slack from products as they move along a product path within a product packaging facility and are therefore space efficient.

[0014] As used herein, "slack" is understood to include liquids and / or solids that travel with or are mixed with a product (e.g., food) and have dimensions significantly smaller than the dimensions of the product. Thus, solid slack, or solids in a slack that is composed of both liquids and solids, can be separated or distinguished from the product with which they are mixed based on size. For example, solid slack can be in the form of a powder or particulates, the product being significantly larger. Solid slack can have average dimensions that are at least 5 times, more typically at least 10 times smaller than the average dimensions of the product in the product-slack mixture. In a further example, solid slack can be even smaller relative to the product, having dimensions that are 50 to 100 times smaller than the product. As an example, sugar confectionery often has a size of about 20 to 30 mm, while powdered sugar (also called icing sugar) that forms the slack has an average particle size of about 0.05 mm. Breaded foods often have a size of 50 to 150 mm, while breaded foods have a size of about 0.5 to 2 mm.

[0015] According to one aspect of the invention, a hopper for separating slack from a mixture of product and slack is provided, the hopper comprising a first gate movable between respective open and closed positions, and a slack remover. The first gate and the slack remover are arranged to define a first product receiving volume therebetween when the first gate is in its closed position, the slack remover comprising a first internal chamber for receiving slack and a first filter wall separating the first internal chamber from the first product receiving volume, the first filter wall being configured to prevent the passage of product but allow the passage of slack. The first gate provides a first path for product to exit the first product receiving volume when the first gate is in its open position. When the first gate is in its closed position, the first path is closed and product may be retained within the first product receiving volume. The slack remover is configured to remain substantially stationary as the first gate moves between its respective open and closed positions.

[0016] The use of such hoppers to remove excess slack from a product path (i.e., a continuous stream of product, or a continuous portion of a product's movement) increases the reliability of the product handling system and improves the quality of the final product. It will further be appreciated that the present invention provides a particularly rapid and efficient means of removing slack from a product path. Slack can be removed from the product while it is settling in the hopper, without significantly delaying the discharge of the product from the hopper. Thus, slack can be removed from an existing stream of product or product portions without significantly impacting the hopper's throughput and / or the output of the wider system.

[0017] The hopper according to the invention is particularly space-efficient since the part for dividing or separating the slack from the product, i.e. the slack remover, is provided within the hopper, and furthermore the hopper according to the invention can be easily retrofitted to product handling machines and can replace existing hoppers that are not suitable for separating slack from the product.

[0018] Furthermore, the hopper according to the invention is simple to design and manufacture and has a long service life because the slack remover is substantially stationary while the hopper receives the product, separates the slack, and dispenses the product. There are no additional moving or dynamic parts compared to a conventional hopper without a slack remover. By substantially stationary, it is meant that the slack remover does not move significantly relative to the rest of the hopper components, except for the first gate which is movable. Vibrations may be transmitted to the slack remover when the first gate is opened and closed, but apart from that, the slack remover remains stationary during use. Thus, in use, the slack remover may be fixed relative to the rest of the hopper components. The slack remover may be unpowered and not directly connected to an actuator.

[0019] The hopper separates the slack from the product when the first gate is in the closed position and a mixture of products is fed (i.e., introduced) into the product receiving volume. For example, the product or an existing mixture of product and slack can be introduced through an opening into the product receiving volume. Such an opening is preferably located at the top of the hopper, allowing the product to enter or fall into the hopper by gravity. In this arrangement, the slack passes from the product receiving body to the first internal chamber of the slack removal body, where it is subsequently collected or discharged. Any excess slack separated and collected using this device may be reintroduced and reused in the production line upstream of the device to reduce waste. The product (and remaining slack) held in the product receiving volume can then be discharged or exit the hopper by opening the first gate. Thus, it can be seen that the product introduced into the product receiving volume while the first gate is closed will remain in the product receiving volume until the first gate is opened.

[0020] The amount of slack removed by the hopper from the product and slack mixture may depend on the length of time the mixture spends in the hopper (i.e., the "residence time" of the product in the hopper). Similarly, the percentage of slack removed by the hopper may depend on the particular product and slack at issue. For example, in preferred embodiments, at least 15% of the slack, by weight and / or volume, may be removed from the mixture introduced into the hopper, more preferably 25%, even more preferably 50%, even more preferably 75%, and even more preferably 95%.

[0021] It is particularly beneficial to remove slack from the product and slack mixture at the hopper compared to other stages of the production line. This is because the product may fall or drop significantly into the hopper (e.g., from a product supplying device such as a dispersion feeder, screw feeder, conveyor, or other suitable machine). This drop may cause a significant amount of slack when the product bumps or crashes into the hopper. Thus, the device according to the present invention can remove the slack quickly after it has been generated and before it is transferred to a downstream product processing machine or before the product is dispensed into packages in a packaging machine. In particular, it may be desirable to provide a slack removal hopper as the final hopper before the food product is provided to the packaging machine packages. This is because slack is typically generated whenever the product hits a surface such as the inside of a hopper. A single slack removal hopper provided as the final hopper before packaging (i.e., as the final hopper before the packaging machine) can thereby act to remove all slack at the last stage where a lot of slack is generated, minimizing the amount of slack in the final packaged product. For example, a slack removal hopper may provide product along a first path that leads directly or indirectly to a package in a packaging machine. For example, the product may drop directly from the hopper into the package or may be conveyed along one or more funnels or chutes into the package. Such final hoppers are often referred to as timing hoppers because they may dispense their contents at a timed interval to accommodate the operation of a subsequent packaging machine (e.g., a bag make machine or a vertical fill form seal VFFS machine).

[0022] Typically, the hopper is capable of receiving a series of product portions, each product portion containing one or more product items. The dividing up of the continuous product stream may be accomplished by a upstream feeding device, such as a computer-controlled weigher or volumetric filler. However, alternatively, the hopper itself may act to divide a substantially continuous product stream. One or more product items may accumulate together in the product receiving volume before being discharged (i.e., dispensed or discharged) together along a first path by opening a first gate.

[0023] The first gates may move between their respective open and closed positions by rotating about a hinge (e.g., a respective hinge). Alternatively, the first gates may slide between their respective open and closed positions. The first gates may be driven by any suitable motor or actuator, such as a Harmonic Drive® (also known as a harmonic gear motor), a linear servo motor, a pneumatic actuator, or the like.

[0024] The slack remover body is preferably hollow and defines a first internal chamber for collecting slack that has passed through the first filter wall. The internal chamber is a volume defined or enclosed within the slack remover body.

[0025] Preferably, the slack remover is removable and can be removed from the remaining components of the hopper. In other words, the slack remover is preferably removably secured (i.e., coupled) to the remaining components of the hopper. In this manner, the slack remover may remain stationary during use, but the body can be removed and removed from the hopper for emptying, cleaning, and / or maintenance. For example, the slack remover can be periodically replaced with a new slack remover.

[0026] Preferably, the slack remover is coupled to the remaining components of the hopper by a mechanism configured to be manually operated to release the slack remover without the need for tools. Such a mechanism may be referred to as a quick release mechanism. In some embodiments, the quick release mechanism comprises a latch, clip or clamp. However, in a particularly preferred embodiment, the slack remover is connected to the remaining components of the hopper by a bolt or screw, the head of which is fitted with a lever handle to allow the bolt or screw to be manually engaged and disengaged. However, in other embodiments, the slack remover may be bolted or screwed to the remaining components of the hopper using conventional bolts or screws. These bolts or screws may be removed using a screwdriver, spanner or socket wrench.

[0027] In further embodiments, the slack remover can be permanently attached to other components of the hopper. For example, the slack remover can be welded, riveted, or formed continuously with other components of the hopper. For example, the slack remover can be welded to one or more chutes through which product and slack are introduced into the hopper and / or welded to one or more hinges about which a gate rotates relative to the hopper.

[0028] Preferably, the first internal chamber of the slack remover has an opening through which the slack can be removed. Thus, the slack collected in the first internal chamber can be discharged from the slack remover while the slack remover is in position in the hopper (e.g. during use). For example, the slack may be continuously or periodically removed from the opening. However, alternatively, the first internal chamber of the slack remover may be removed from the slack remover so that the slack remover can be emptied and / or cleaned (as described above). The opening is preferably provided separately from the hole in the filter wall and may be provided in a wall separate from the filter wall of the slack remover.

[0029] In a particularly preferred embodiment, the first path by which the product can exit the hopper when the first gate is opened is angled and / or laterally offset with respect to the path by which the slack can exit the first internal chamber through the opening described above, thereby reducing the risk that slack separated from the product and slack mixture in the hopper will be inadvertently re-entered into the production line.

[0030] Preferably, the opening of the first internal chamber is configured to be connected to a vacuum pump arranged to remove slack from the first internal chamber. Providing a vacuum pump to withdraw slack from the first internal chamber of the slack remover is a convenient and automatic means of emptying the first internal chamber. It also reduces the risk of slack accumulating or clogging the first internal chamber.

[0031] In a preferred embodiment, a vacuum pump may be provided having sufficient strength to exert a suction force on the contents of the first product receiving volume to draw the slack into the first internal chamber of the slack remover. In an alternative embodiment, the internal chamber may be manually emptied. To that end, a system may be provided that includes a hopper and a vacuum pump.

[0032] The vacuum pump has a rated power of 2-8 kW, more preferably 4-6 kW. Preferably, the vacuum pump is explosion proof, especially when the slack is a particulate or powder such as sugar. In some instances, the vacuum pump may be a central vacuum pump within a larger plant or system. In such cases, one vacuum pump may be configured to couple to multiple machines and may be configured to couple to two or more hoppers.

[0033] Preferably, the opening is provided in a bottom surface of the first inner chamber, so that slack can be easily removed from the inner chamber as slack typically accumulates at the bottom of the inner chamber due to gravity.

[0034] Preferably, the bottom surface of the first internal chamber is angled towards the opening, such that gravity tends to move the slack along the first internal chamber towards the opening. It will be appreciated that the bottom surface of the trough is therefore not parallel to either the horizontal or vertical axis in use. The slack can flow along the bottom surface of the trough towards the opening. This is particularly effective when the slack is in the form of a liquid, fine particles or powder. Thus, gravity tends to exit the first internal chamber, and the suction force required to empty the first internal chamber can be (for example) reduced. Hence, recovery of the slack from the first internal chamber is simplified. Nevertheless, in a further embodiment, the trough can have a bottom that is not angled and extends substantially horizontally in use.

[0035] The combination of an angled bottom and a vacuum pump is particularly effective because slack is much more likely to migrate across the angled surface under suction, making it easier to retrieve.

[0036] Preferably, the first filter wall has one or more holes, each hole sized to allow slack to pass therethrough but prevent product from passing therethrough. Thus, slack can pass through the openings (i.e. holes or perforations extending entirely through the first filter wall) but product cannot. It will be appreciated that the multiple holes can be arranged in a wide variety of layouts across the surface of the filter wall. Additionally, the holes can be of various sizes and shapes. The holes can be designed to suit the product and slack combination for which the hopper is to be used.

[0037] Preferably, at least one dimension of the holes is smaller than the smallest dimension of the product for which the hopper is used, so that the product cannot pass through the holes. Also preferably, the dimensions of the holes can be selected to be larger than the largest dimension of the slack, so that the slack can pass through the holes.

[0038] For example, the smallest dimension (i.e. minimum dimension) of each hole in the planar filter wall is preferably in the range of 0.1 cm to 1 cm, more preferably in the range of 0.1 cm to 0.5 cm. The term "minimum dimension" is understood to mean the smallest dimension of the hole in the plane of the first filter wall. For example, if the hole is circular, its minimum dimension will be the diameter of the hole. On the other hand, if the hole is elongated, its minimum dimension will be its width perpendicular to the direction in which the hole extends.

[0039] The above mentioned dimensions are suitable for a wide range of applications, especially for the food packaging industry. For example, filter walls with holes having at least one dimension ranging from 1 cm to 0.1 cm are suitable for separating loose sugar from sweetened confectionery, excess seasoning from chips and chips, excess marinade from marinated meat products. However, openings of different dimensions can be selected for different mixtures of products and slacks.

[0040] In a preferred embodiment, the first filter wall comprises a filter, mesh, grid, grill, gauze, sieve, or net. Thus, the first filter wall can have a plurality of holes arranged in a regular or irregular array. Thus, at least a portion of the filter wall is formed as a filter, mesh, grid, grill, gauze, sieve, net, or other suitable structure.

[0041] In contrast, the remaining walls of the slack remover, the first gate, and other components of the hopper that define the product receiving volume are preferably continuous, e.g., formed of a continuous sheet material. For example, these components and walls may be constructed of sheet or plate metal without holes or openings. Thus, these components will impede the passage of both product and slack.

[0042] In a preferred embodiment, the first filter wall includes a slot therethrough, the slot being sized to allow slack to pass therethrough but prevent product from passing therethrough. And when the first gate is in its closed position, the first gate is positioned such that its free end is adjacent to and / or into the slot and the inner surface of the first gate is angled towards the slot, such that slack is likely to move along the first gate towards the slot under gravity. Thus, slack may pass from the first product receiving volume through the slot in the first filter wall into the first internal chamber. Slack in the product receiving area is likely to fall under gravity onto the inner surface of the first gate and slide or move along the angled first gate to the free end of the gate and through the slot into the first internal chamber. By angled, it is meant that the first gate is configured such that the inner surface is not parallel to either the horizontal or vertical axis, but instead is angled towards the slot, when in use and in the closed position. The free end of the first gate is understood to be the end that is not fixed to the end. For example, the free end may be at an opposite end of the first gate relative to the hinge about which the first gate pivots. The slot is therefore preferably located at a location in the first filter wall where the first gate and the first filter wall would intersect when the first gate is in its closed position if the slot were not present and / or the length of the first gate were greater. Such a slot may also be provided in combination with other holes in the first filter wall. However, this is not required and the first filter wall may consist of only the slot as a single opening for removing slack.

[0043] This slot and the aforementioned hopper arrangement provide a special advantage in slack removal that may not be immediately apparent without considering how the slack and product move. In many product and slack combinations, especially in those instances where the slack consists of powders or fine particles, the slack will tend to fall by gravity faster than the product. The larger products tend to slow down due to collisions with themselves and with the surfaces of the passages or chutes they pass through. Thus, as a mixture of product and slack is fed into the hopper, there will be a higher concentration of slack and a reduced amount of product at the bottom (i.e., earliest) portion of the mixture. As the product level drops, the slack in this initial portion of the mixture will strike the angled inner surface of the first gate and be quickly directed into the slot and slack removal chamber before the majority of the product settles into the product receiving volume.

[0044] The slot may have a number of projections extending from a long side of the slot towards the opposite side of the slot. The projections thus form "teeth" that extend across a portion of the slot. The teeth act as a filter, preventing the passage of larger objects (such as product) while allowing the passage of smaller objects (such as slack). The projections may extend across at least 25% of the width of the slot, more preferably at least 40% of the width of the slot, and even more preferably at least 50% of the width of the slot.

[0045] Additionally, because the inner surface of the first gate is angled toward the first filter wall, the product receiving volume has a substantially triangular cross section, so that relatively little product settles near the slots within the apex or point of the triangular cross section, and slack therefore passes relatively freely across the inner surface of the first gate, through the slots, and into the slack removal body.

[0046] Preferably, the slot is wider than the free end of the first gate so that slack moving at any point across the width of the first gate can easily enter the slack remover. In other words, the slot extends continuously across the entire width of the free end of the first gate when the first gate is in its closed position so as to not impede the passage of slack along the width of the free end of the first gate.

[0047] In a preferred embodiment, when the first gate is in its closed position, it is angled towards the first filter wall at an angle of less than 45 degrees to the vertical axis, more preferably less than 40 degrees, and even more preferably less than 30 degrees. A steeper angle of the first gate will encourage slack to flow across its surface towards the first filter wall, so a steeper angle will allow for greater slack removal, especially when dealing with solid slack.

[0048] In a particularly preferred embodiment, the hopper may include one or more exterior holes extending between the first internal chamber and the exterior of the hopper when the first gate is in the open and closed positions, respectively, and the exterior holes are sized to allow slack to pass therethrough but not product to pass therethrough such that slack in the air outside the hopper can enter the slack removal body through the exterior holes.

[0049] The external holes solve a recognized problem when handling fine powders and particulate slack, such as icing and powdered sugar. When the gates of hoppers handling such fine powders are opened and closed, a dust of airborne slack is likely to be generated. The fine slack is expelled from the hopper by dynamic forces. Thus, a cloud of airborne slack may exist around the hopper when it is in use. The external holes extending between the exterior of the hopper and the inner chamber of the slack removal chamber allow this airborne slack to collect in the inner chamber.

[0050] The external holes of the slack remover are particularly advantageous in combination with a vacuum pump connected to the opening of the internal chamber. The vacuum pump can apply suction to the air surrounding the hopper through the external holes. The slack in the air surrounding the hopper is thus collected in the internal chamber and sucked away. The slack thus collected can be disposed of or reused as appropriate.

[0051] For example, the exterior aperture can be formed in an outer wall of the slack removal chamber that separates the first interior chamber from the exterior of the hopper and thus defines a portion of the exterior of the hopper regardless of the location of the hopper's gate. In a preferred embodiment, the slack remover is wider than the first gate such that the outer wall of the slack remover protrudes laterally beyond the boundary of the first gate, thereby allowing a greater percentage of the airborne slack to be removed from the air surrounding the hopper.

[0052] In a preferred embodiment, the outer wall of the slack remover and the filter wall are continuous and / or coplanar, however, this is not required and in other examples the walls may be disposed perpendicular to one another.

[0053] Preferably, the hopper is configured such that vibrations caused by opening and / or closing the first gate are transmitted to the slack remover and its contents. As such, the slack in the slack remover is subjected to vibration forces and agitated by the movement of the first gate. As such, the slack is less likely to form lumps or clumps. In embodiments where the slack remover chamber has an opening and / or a sloped bottom for discharging the slack, the vibrations can also encourage the slack to move across the slack remover chamber towards the opening. As such, in these instances, the slack remover is more likely to empty.

[0054] In a preferred embodiment, the first gate comprises side walls disposed on either side of the first product receiving volume when the first gate is in its closed position, and the side walls of the first gate are configured to contact the slack remover body when the first gate is in its closed position. In this manner, the first product receiving volume can be defined between the filter wall of the slack remover body, the side walls of the first gate, and other portions of the first gate. By contacting the filter wall, the side walls can prevent product and slack from exiting the first product receiving area when the first gate is closed. Furthermore, when the first gate is closed and its side walls are brought into contact with the filter wall of the slack remover body, vibrations can be transmitted to the slack remover body.

[0055] In a particularly preferred embodiment, the hopper is configured to open and / or close the first gate in two separate steps. Thus, the opening and / or closing are two separate movements with a gap or interval between them. For example, the hopper can be configured to close the first gate in a first closing step, which moves the first gate to an intermediate position between the open and closed positions, followed by a second closing step, which moves the first gate from the intermediate position to the closed position. The gate is held substantially stationary in the intermediate position between the first and second closing steps. The time between the two closing steps is at least 100 ms, preferably at least 200 ms, more preferably at least 400 ms. This two-step process of pausing the first gate's movement as it moves between the open and closed positions (or between the closed and open positions) is highly dynamic and can transmit large vibrations to the slack remover and its contents. Thus, the slack can be transported towards the opening of the first internal chamber described above for removal. In a preferred embodiment, the intermediate position is closer to the closed position than to the open position. In a particularly preferred embodiment, the intermediate position is between 75-100%, more preferably between 90-98%, and even more preferably between 94-96% of the total distance or angle from the open position to the closed position. By moving the intermediate position closer to the closed position in this manner, a high level of force is transferred to the slack remover, especially when a Harmonic Drive® motor is used.

[0056] The first gate, slack remover, and / or other components of the hopper may be formed of metals, alloys, plastics, or composite materials, such as stainless steel, steel, aluminum, etc. (although other suitable materials may be used). In a preferred embodiment, the gate and walls of the hopper may be constructed of bent stainless steel (although this is not required). If the hopper is intended for use in the food packaging industry, preferably the components are constructed of food-safe materials. The hopper may be formed of multiple layers of material. For example, each filter wall may be constructed of one or more layers of material secured together.

[0057] In some examples, the surface roughness Ra (i.e. the average deviation of the surface) of the first gate, the slack remover, and / or the further components or walls of the hopper may be less than 10 μm, more preferably less than 5 μm, more preferably less than 2 μm. In particularly preferred examples, the surface roughness is less than or equal to 1.6 μm. A material with a low surface roughness can prevent the product and / or slack from sticking or adhering to the hopper. Additionally or alternatively, the first gate, the slack remover, and / or the further parts or walls may have a surface relief configured to reduce friction between the hopper and the product and / or slack, so as to prevent the product and / or slack from adhering to the surface of the hopper. However, in further examples, it may be desirable to leave the surface rough.

[0058] In some embodiments, the hopper may include a chute or surface configured to direct the mixture toward the first filter wall as it enters the product receiving volume, such that the mixture of product and slack contacts the first filter wall at a substantially perpendicular angle. Alternatively, a feeder or other component located upstream of the hopper may be configured to guide or distribute the mixture into the hopper at a substantially perpendicular angle to the first filter wall. For example, the product and / or slack may contact the first filter wall as it travels along a path having an average angle greater than 45 degrees, more preferably greater than 60 degrees, and even more preferably greater than 75 degrees, relative to the surface of the first filter wall. By positioning the hopper such that the mixture strikes the wall at these relatively high angles, the proportion of slack removed through the first filter wall may be increased. However, this is not required.

[0059] In a particularly preferred embodiment, the hopper has a plurality of movable gates (e.g., a first gate and a second gate) and two corresponding product receiving volumes (e.g., a first product receiving volume and a second product receiving volume) separated by at least one wall of the hopper and / or slack remover that can prevent product introduced into the first product receiving volume from entering the second product receiving volume, and vice versa.

[0060] Providing a hopper with multiple product receiving volumes that are opened and closed by separate gates provides increased flexibility and allows for increased product throughput without a corresponding increase in hopper size.

[0061] A significant delay in the operation of a hopper with a single gate is associated with the so-called settling time, when the product and slack mixture is first introduced into the hopper. It takes time for the product to enter the hopper, settle and for the slack to be separated from the mixture. To increase the throughput, it is also possible to feed the product from different product intakes in an alternating manner. While a first product receiving volume is filled with a product and slack mixture and the corresponding gate is closed to separate the slack from said mixture, a second product receiving volume has its gate open to feed the product from which the slack has already been removed (and vice versa). In this way, the operation of the gates and product receiving volumes in an alternating manner allows a large amount of slack to be removed from each portion of the product and slack mixture without a significant delay between successive portions fed from the hopper.

[0062] Alternatively, the gates can be controlled to operate separately or together depending on (for example) the weight of the contents and the desired portion size to be dispensed, an added flexibility not possible with a hopper having a single product receiving area and a single gate.

[0063] More particularly, the hopper preferably has a second gate movable between respective open and closed positions. The second gate and the slack remover are arranged to define a second product receiving volume therebetween when the second gate is in the closed position. The second gate is configured such that when the second gate is in its open position a second path is provided for product to exit the second product receiving volume and when the second gate is in its closed position said second path is closed and product may be retained within the second product receiving volume. Thus product is retained in the first and second product receiving volumes and remains substantially stationary while the respective gates are closed.

[0064] Preferably, the hopper is also configured to remove slack from the mixture of product and slack that is introduced into the second product receiving volume.

[0065] Indeed, in a particularly preferred embodiment, the first and second gates are opposed and the slack remover is disposed between the opposed first and second gates. The slack remover comprises a second internal chamber for receiving slack and a second filter wall separating the second internal chamber from the second product receiving volume, the second filter wall being configured to prevent product from passing through but to allow slack to pass through. Thus, slack may be removed from the second product receiving volume in a similar manner to slack from the first product receiving volume and product may be retained in the second internal chamber.

[0066] In such an example, the two movable gates are opposed and the slack remover is disposed between them. Thus, the hopper may be symmetrical about a centerline extending through the slack remover (assuming the first and second movable gates are disposed at corresponding positions). The two halves of the hopper may be operated simultaneously or alternately. However, in further embodiments, the product receiving volume and the gates may be provided in further arrangements, for example linearly on the same side of the slack remover.

[0067] In a preferred embodiment, the first and second inner chambers of the slack removal chamber are the same chamber, in other words the slack remover constitutes a single inner chamber into which slack from both the first receiving volume and the second receiving volume can enter through the respective first and second filter walls.

[0068] Providing a slack remover between two product receiving volumes is space efficient. Additionally, it is quick and easy to remove slack using the same internal chamber. Additionally, because the slack remover in these embodiments is centrally located within the hopper, there is a low risk of slack leaking or being released from the slack remover's internal chamber and unintentionally re-entering the production line.

[0069] In some embodiments, the slack receiving body includes an internal baffle in its single internal chamber, the internal baffle configured to prevent slack from entering the internal chamber through the first filter wall and immediately flowing in through the second filter wall, or from entering through the second filter wall and flowing out through the first filter wall. The internal baffle may be disposed between the first and second filter walls and configured to prevent slack from passing therethrough (e.g., formed of a continuous sheet material). In this manner, the internal baffle separates or isolates the paths of slack entering the slack removing body from the respective filter walls. The internal baffle may extend vertically along a centerline of the slack receiving body.

[0070] The second gate, the second product receiving volume, the second filter wall, and the second internal chamber (if separate from the first internal chamber) may include any of the features and provide any of the corresponding advantages described above with respect to the first gate, the first product receiving volume, the first filter wall, and the first internal chamber, respectively. Similarly, the second gate and the second product receiving volume may be operated according to the steps described above for the first gate and the first product receiving volume.

[0071] Preferably, the different paths (first and second paths) along which the product is fed are parallel. In a preferred embodiment, the products distributed along the first and second paths are transported to the same downstream equipment, e.g., the same packaging machine. However, these features are not required and the products from each product receiving area may be directed or transported to different locations. For example, the products fed from separate gates may be directed to different discharge paths, e.g., different feed paths to a twin bagger, a double lane boxer, a tin canner, etc.

[0072] Preferably, the hopper is a hopper suitable for use in a computer controlled weigher, a multi-head or combination weigher, a linear weigher, a cup filler, and / or a volumetric filler. For example, the hopper is suitable for use in a combination weigher (also commonly referred to as a multi-head weigher). Such equipment quickly and efficiently divides a stream of product into individual portions for packaging.

[0073] For example, the hopper may be a timing hopper, a weigh hopper, a pool hopper, a booster hopper, an output hopper, or a discharge hopper. In many food packaging systems, the use of a hopper according to this aspect of the invention as a timing hopper, which is the final hopper before the product is passed to a packaging machine, is particularly beneficial because it allows slack to be removed from the product just before it is packaged. The timing hopper dispenses its contents periodically, usually at regular intervals, in correspondence with the downstream packaging machine (or other machine). As discussed above, removing slack from the final hopper before packaging (i.e., the last hopper before the packaging machine) helps to remove all slack at the last stage where a large amount of slack occurs, minimizing the amount of slack in the final packaged product and / or the amount of slack that is trapped in the seams of the packaged product.

[0074] According to a further aspect of the present invention there is provided a system comprising one or more hoppers according to any of the preceding claims and a computer controlled weigher and / or packer.

[0075] If the system has a computer-controlled weigher, the hopper may be a hopper within the computer-controlled weigher, or may be configured to dispense product to the computer-controlled weigher, or may receive product from the computer-controlled weigher.

[0076] In a preferred embodiment, the computer controlled weigher is a combination or multi-head weigher, a linear weigher, a cup filler or a volumetric filler, all of which are examples of feeders suitable for the hoppers and systems described above. Such weighers are particularly fast and efficient at dividing a continuous product stream into product portions of fixed weight. However, other weighers and feeders may also be used.

[0077] In preferred examples, the packaging machine is a bag-maker, a vertical fill form seal (VFFS) machine, a cartoner, a cartonizer or a canner, although other packaging machines may be provided. The bag-maker or VFFS machine is preferably configured to receive the product from a hopper.

[0078] Most preferably, the hopper is a timing hopper located between the computer controlled weigher (feeder) and the packaging machine. In such a case, the computer controlled weigher (feeder) may dispense product into the hopper, which then feeds the product into the bag making or VFFS machine. Slack may travel with the product fed from the computer controlled weigher (feeder) into the hopper and / or slack may be generated upon entering the hopper. In either case, the slack may be removed from the mixture of product and slack in the hopper by the methods described above.

[0079] In a preferred embodiment, the system includes a vacuum pump. The vacuum pump may be configured to be connected to an opening of an internal chamber (e.g., the first and / or second internal chambers described above) of the slack remover or to remove slack from the internal chamber, as described above. The vacuum pump may be configured to operate continuously or periodically. In a preferred embodiment, the vacuum pump has sufficient power to provide a suction force to draw slack in the air from outside the hopper through holes in the outer wall of the slack remover into the first and / or second internal chambers of the slack remover.

[0080] The system according to this aspect of the invention provides corresponding advantages and can comprise any of the features described above for the hoppers of the preceding aspects of the invention, which provide a compact and efficient means of removing slack from a packaging system.

[0081] Preferably, the system is a product packaging system, more preferably a food packaging system, for example the system may be configured to portion and / or package confectioneries, crisps, chips and other food products.

[0082] According to a further aspect of the invention there is provided a method of separating slack from a product and slack mixture using a hopper or system according to the preceding aspects of the invention, the method comprising the steps of: (a) feeding the product and slack mixture into a first product receiving volume of the hopper when a first gate is in its closed position such that product is retained in the first product receiving volume and at least some slack from the mixture passes through a first filter wall into a first internal chamber of the slack remover, and (b) moving the first gate of the hopper to its open position such that the remaining contents of the first product receiving volume exit the hopper.

[0083] Thus, the method according to the invention quickly and efficiently removes excess slack from the product and slack mixture and dispenses a product with a reduced level of slack. While the mixture is in the hopper, the slack tends to pass through the first filter wall and is retained in the first internal chamber of the slack remover. The residence time of the mixture in the hopper, i.e., the time between introducing the mixture into the hopper and the first gate opening to discharge the product, can be adjusted to control the amount of slack removed from the final product.

[0084] The slack remover preferably remains substantially stationary during the method, so that there is preferably no significant movement of the slack remover as the first gate is opened and closed.

[0085] Here, the action "feeding a mixture of product and slack to the product receiving volume of a hopper" is understood to refer at least to a situation where a mixture of product and slack is introduced (i.e., distributed) into the product receiving volume and / or a situation where slack is generated when the product is introduced into the product receiving volume. In the former situation, the product is fed into the hopper with slack, i.e., the mixture of product and slack is generated upstream of the hopper, whereas in the latter situation, slack is generated when the product enters the hopper. For example, the product may break as it falls into the hopper, thereby fragmenting and generating slack.

[0086] The method further comprises (c) moving the first gates to their respective closed positions, the method including repeating steps (a)-(c). In this manner, the method may be performed iteratively to remove slack from successive portions of the product prior to packaging.

[0087] In a preferred embodiment, step (c) includes two separate closing steps, namely a first closing step for moving the first gate to an intermediate position between the open position and the closed position, followed by a second closing step for moving the first gate from the intermediate position to the closed position. The first and second closing steps are separate and consecutive. Thus, the first gate is held stationary for a predetermined time, for example at least 100 ms, between the two closing steps. This two-step process is dynamic and may transmit large vibrations from the gate to the slack remover. Thus, the slack in the slack remover may be transported towards the opening of the first internal chamber described above for removal. In a preferred embodiment, the intermediate position is closer to the closed position than the open position. In a particularly preferred embodiment, the intermediate position is a position that is in the range of 80-100%, more preferably 90-98%, and even more preferably 94-96% of the total distance or angle from the open position to the closed position. This intermediate position close to the closed position transfers high levels of force to the slack remover, especially when using HarmonicDrive® motors.

[0088] In a preferred embodiment, steps (a) and (b) are spaced apart by at least 100 ms, preferably at least 200 ms, more preferably at least 400 ms. These values ​​indicate suitable residence times for removing slack from the mixture when dealing with a variety of products. In particular, these times are suitable for many mixtures containing food products such as sugar confectionery. As mentioned above, a larger delay can ensure that a greater proportion of slack is removed from the product and slack mixture. However, if the hopper repeatedly delivers products to the packages of the packer, it is desirable for each iteration of step (c) to occur at most 1000 ms after the preceding iteration of step (c), preferably at most 800 ms after the preceding iteration of step (c), more preferably at most 600 ms after the preceding iteration of step (c), and most preferably at most 500 ms after the preceding iteration of step (c). Reducing the delay between each iteration helps maintain the overall throughput of the system, which is particularly important when the hopper acts as a bottleneck as a hopper dispensing packages of the packer. A preferred range is for each repetition of step (c) to occur between 200ms and 800ms, preferably between 400ms and 600ms, after the previous repetition of step (c).

[0089] Alternatively or additionally, the method may include the steps of (i) obtaining a time series of weight measurements of the contents of the hopper and / or the first product receiving volume, and (ii) making a determination that the weight of the contents has stabilized based on the weight measurements, with step I being performed only after said determination has been made. In this way, the first gate is opened only after the contents of the first product receiving volume have settled and reached a (sufficiently) steady state. For example, the weight measurements may be taken continuously or periodically (e.g. every 10 ms). In a further example, the weight measurements may be taken at least every 0.5 s, preferably at least every 0.25 s, more preferably at least every 0.1 s, more preferably at least every 0.05 s. The weight of the contents of a particular hopper may be determined to be stable when two or more consecutive measurements (e.g., three consecutive measurements) are the same value and / or when the difference or range between two or more consecutive measurements is less than a predetermined value (e.g., less than 1 g, more preferably less than 0.5 g, even more preferably less than 0.15 g, or less than 1% and more preferably less than 0.5% of the total weight of the contents of the hopper).

[0090] In a preferred embodiment, the method may include the step of (d) collecting the slack received by the slack remover, such that in this step the slack is removed or expelled from the slack remover.

[0091] In a particularly preferred embodiment, this step includes operating a vacuum pump to recover the slack from the slack removal body. Such a vacuum pump may be connected to an opening in the first internal chamber of the slack removal body that is separate from the hole in the filter wall through which the slack may enter the first internal chamber from the product receiving volume, but this is not required. The vacuum pump may be operated continuously or periodically. For example, the vacuum pump may be operated every cycle of the method, or once every 5 or 10 cycles, depending on the slack of interest. Alternatively, the slack may be removed and recovered manually (e.g., by removing the slack removal body from the hopper and cleaning it).

[0092] In a particularly preferred embodiment, the method includes reintroducing the slack into the product manufacturing process at an upstream location. In other words, the separated slack may be reused in upstream machinery. This can eliminate waste, particularly when the slack is a coating. For example, sugar removed from a confectionery and sugar mix can be used to coat more confectionery. Similarly, excess breadcrumbs or marinade that did not adhere to the product can also be reused.

[0093] Preferably, the method is carried out using a hopper including a second gate movable between an open position and a closed position. The second gate and the slack remover are arranged to define a second product receiving volume therebetween when the second gate is in the closed position. The second gate is configured such that when the second gate is in the open position, a second path is provided for product to exit the second product receiving volume, and when the second gate is in the closed position, said second path is closed and product may be retained in the second product receiving volume. The method further comprises (e) feeding a mixture of product and slack into the second product receiving volume of the hopper when the second gate is in its closed position, such that the product is retained in the second product receiving volume and at least some slack from the mixture passes through a second filter wall into a second internal chamber of the slack remover (which may or may not be the same as the first internal chamber), and (f) moving the second gate of the hopper to its open position such that the remaining contents of the second product receiving volume exit the hopper. Steps (b) and (f) may be performed separately or simultaneously.

[0094] As discussed above, providing a hopper with multiple gates and product receiving volumes can achieve higher throughput when the product receiving volumes are alternately filled and discharged. Similarly, multiple product receiving volumes and gates provide increased flexibility since the gates can be controlled (e.g., based on weight and / or the contents of the product receiving volumes) to operate simultaneously or independently.

[0095] It will be appreciated that steps (e) and (f) of the method performed using the second product receiving volume and the second gate correspond to steps (a) and (b) of the method performed using the first product receiving volume and the first gate. Moreover, these steps may include any of the optional or preferred features described above for steps (a) and (b) to provide corresponding advantages. For example, steps (e) and (f) may be performed at least 100 ms apart, preferably at least 200 ms apart, more preferably at least 400 ms apart, and / or step (f) may be performed only if a weight measurement of the hopper and / or the second product receiving volume indicates that the weight of the contents has stabilized.

[0096] The method may also include the additional step of removing the slack remover from the hopper (i.e., from the remaining components of the hopper). The slack remover thus removed may then be cleaned or repaired. Furthermore, the original slack remover may be replaced with another slack remover, thereby allowing the hopper and system to continue functioning while maintaining the original slack remover.

[0097] In a particularly preferred embodiment, the method includes forming the product discharged from the hopper in step (b) or (f) into a packaged article and sealing the packaged article. For example, the product is dispensed into a packaging machine, such as a bagger, VFFS machine, case filler, cartonizer, canner, etc. The packaged product has a significantly reduced level of slack compared to product that has not passed through the hopper or system described above.

[0098] The mixture of product and slack introduced into the product receiving volume may be received from a computer controlled weighing machine such as a combination or multi-head weighing machine, a linear weighing machine, a cup filler or a volumetric filler. Other feeding devices may alternatively be used.

[0099] According to a further aspect of the invention, there is provided a slack remover suitable for use in the hopper and system described above with reference to the preceding aspects of the invention. As described above, the slack remover may be removably connected (i.e. fixed) to the remainder of the hopper. Thus, the slack remover may be provided separately from the remaining components of the hopper. The slack remover of a hopper according to the invention may be replaced or substituted as required.

[0100] It will therefore be seen that the above-described aspects of the invention provide improved apparatus, systems and methods for removing slack from a product and slack mixture, which apparatus, systems and methods are suitable for use in food packaging. [Brief description of the drawings]

[0101] The present invention will now be described with reference to the drawings. [Figure 1a-1d] 1 shows a schematic cross-section of a hopper according to the invention, the figures showing the hopper at different stages of a method for removing slack from a product and slack mixture according to the invention. [Figure 2a-2b] 1a-1d show schematic cross-sections of the hopper of FIG. 1a to 1d implementing a further method for removing slack from a product and slack mixture according to the invention; [Diagram 3] FIG. 4 is a schematic cross-sectional view of a further hopper according to the invention; [Figure 4a] FIG. 4 is a schematic cross-sectional view of a further hopper according to the invention; [Figure 4b] FIG. 4 is a schematic cross-sectional view of a further hopper according to the invention; [Figure 5a-5f] Figure 5 shows a further hopper according to the invention, of which Figures 5a and 5b show the hopper in isometric perspective, Figures 5c and 5d show the hopper in side view and Figures 5e and 5f show the hopper in cross section, and further Figures 5a, 5c and 5e show the hopper in a gated closed configuration and Figures 5b, 5d and 5f show the hopper in a gated open configuration. [Figure 6]FIG. 2 is a schematic cross-sectional view of a system according to the invention, the system including the hopper of FIGS. 5a to 5f. [Figure 7a-7b] A slack remover suitable for use in an embodiment of the present invention is shown in perspective, specifically, FIG. 7a is a perspective view showing the exterior of the slack remover, and FIG. 7b is a cutaway view showing the hopper from the same perspective but showing the interior of the slack remover. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0102] 1a-1d are schematic cross-sectional views of a hopper 10 having a slack remover 20 therein. The hopper 10 is suitable for handling food products such as confectionery, crisps, chips, raw meat, cooked meat, breaded foods, etc. The production of such food products often produces or requires slack in the form of coatings, crumbs, powders, particulates, etc. Such slack may be comprised of liquids and / or solids. The hopper 10 is configured to remove excess slack from products therein.

[0103] Figures 1a to 1d show a hopper 10 together at different stages of a method for removing slack S from a mixture of product P and slack S. As shown, the average dimensions of slack S are approximately an order of magnitude smaller (i.e., at least 1 / 10) than the average dimensions of product P. As an example, product P is a sweet or candy and slack S is excess sugar used to coat the product.

[0104] As can be most easily seen in FIG. 1a, the hopper 10 is symmetrical and has two opposing gates - a first gate 12a and a second gate 12b - on either side of the slack remover 20. The gates 12a, 12b are movable and each is configured to move between a respective closed position (shown in FIGS. 1a, 1b, and 1c) and a respective open position (shown in FIG. 1d). Specifically, each gate 12a, 12b is configured to rotate about a respective hinge 14a, 14b that connects the gate 12a, 12b to a respective stationary wall 16a, 16b of the hopper 10.

[0105] When the gates 12a, 12b are in the closed position, two product receiving volumes - a first product receiving volume 18a and a second product receiving volume 18b - are defined between the slack remover 20 and the respective gates 12a, 12b. The product receiving volumes 18a, 18b are thus located on opposite sides of the slack remover 20. Product P is introduced or dispensed into these vacant product receiving volumes 18a, 18b through upwardly facing openings 17a, 17b in the top of the hopper 10.

[0106] The slack remover 20 has an internal chamber 22 that is triangular in cross section (although this is not required) and is configured to receive slack S from the product receiving volumes 18a, 18b of the hopper 10. The internal chamber 22 is an enclosed cavity within the slack remover 20.

[0107] The interior chamber 22 of the slack remover 20 is separated from each product receiving volume 18a, 18b by a respective filter wall 24a, 24b. In other words, the first product receiving volume 18a is separated from the interior chamber 22 by the first filter wall 24a, while the second product receiving volume 18b is separated from the interior chamber 22 by the second filter wall 24b.

[0108] As can be seen, each filter wall 24a, 24b has a plurality of holes 26 extending therethrough (i.e., the holes 26 are holes extending through the filter wall). Thus, at least a portion of the filter walls 24a, 24b can be formed as a mesh, grill, grate, filter, gauze, sieve, or net. The holes 26 are sized to allow slack S to pass through the holes 26 but not product P. Thus, at least one dimension of each opening is smaller than the smallest dimension of the product intended for use with the hopper 10 such that the product P cannot pass through the holes 26. Meanwhile, each dimension of the holes 26 is larger than the largest dimension of the slack S intended for use with the hopper 10. In contrast, the gates 12a, 12b, the stationary walls 16a, 16b, and the remaining walls of the slack remover 20 are continuous (i.e., without openings) such that neither product P nor slack S can pass therethrough.

[0109] The operation of the hopper 20 shown in Figures 1a to 1d will now be explained with reference to diagrams illustrating successive steps of the method according to the invention for removing slack S from a mixture of product P and slack S.

[0110] FIG. 1a shows an arrangement in which both the first and second gates 12a, 12b are closed and there is no slack S or product P in the hopper. As mentioned above, in this arrangement, a product receiving volume 18a, 18b is formed between each gate 12a, 12b and the slack remover body 20. The free ends of the first and second gates 12a, 12b, i.e., the ends of the first and second gates 12a, 12b, contact the respective filter walls 24a, 24b of the slack remover body 20. Specifically, each gate 12a, 12b is angled from its hinge 14a, 14b to its free end toward the slack remover body 20. In the hopper 10 shown in FIG. 10, when the gates 12a, 12b are in their respective closed positions, the angle between each gate 12a, 12b and the vertical axis is about 40 degrees. However, in a more preferred embodiment, during use, the angle between each gate 12a, 12b in the closed position and the vertical axis is preferably less than 45 degrees, more preferably less than 40 degrees, and even more preferably less than 30 degrees.

[0111] With the hopper 10 in this initial closed configuration, product (e.g., product P in a mixture of product P and slack S) is introduced into each product receiving volume 18a, 18b, as shown in FIG. 1b. The mixture of product P and slack S is introduced into the first product receiving volume 18a, as indicated by arrow I1. Similarly, the mixture of product P and slack S is introduced into the second product receiving volume 18b, as indicated by arrow I2. As shown, the product P and slack S are distributed into the hopper 10 by gravity, although this is not required. The product P and slack S may also be distributed from computer controlled weighers or other feeding devices (not shown).

[0112] In Fig. 1b, it can be seen that a mixture of product P and slack S is distributed to the product receiving volumes 18a, 18b. In other words, in the example shown in Fig. 1b, slack S is generated upstream of the hopper 10. However, alternatively or additionally, slack S may be generated as the product P enters the hopper 10. For example, if the product P falls from the feeder into the hopper 10 and hits the gates 12a, 12b and the slack remover 20, the product may be damaged and / or broken into pieces. It will therefore be understood that the slack S in the mixture of product P and slack S supplied to the product receiving volumes 18a, 18b may be introduced into the volume, i.e. distributed into the volume, or may be generated within the volume.

[0113] Product P delivered to the product receiving volumes 18a, 18b is retained within the volumes 18a, 18b while the respective gates 12a, 12b are closed. This arrangement in which product P is retained in the product receiving volumes 18a, 18b of the hopper is shown in Figure 1c.

[0114] In contrast, slack S within the mixture of product P and slack S can exit the product receiving volumes 18a, 18b and enter the interior chamber 22 of the slack removal body 20 through holes 26 in the respective filter walls 24a, 24b. The movement of slack S from the first product receiving volume 18a through the holes 26 in the first filter wall 24a is indicated by arrow R1 in FIG. 1c, while the movement of slack S from the second product receiving volume 18b through the holes 26 in the second filter wall 24b is indicated by arrow R1 in FIG. 1c.

[0115] This movement of slack S occurs by gravity. The slack S in each product receiving volume 18a, 18b tends to flow through a mixture of product P and slack S across the inner surface of the respective sloped gate 12a, 12b toward the respective filter wall 24a, 24b. However, in a further embodiment, a vacuum pump can be connected to an opening (not shown) in the inner chamber 22 to apply suction to draw the slack from the product receiving volumes 18a, 18b into the inner chamber 22.

[0116] It will be appreciated that this method does not involve removing all of the slack S from the mixture in the product receiving volumes 18a, 18b. Instead, in practice, it is common for a small amount of slack S to remain in the product receiving volumes 18a, 18b with the product P, as shown in FIG. 1c. Furthermore, the percentage of slack S that is removed from the mixture of product P and slack S can be controlled (for example) by varying the so-called "residence time" of the product P in the hopper 10, i.e., the time between feeding (i.e., introducing) the product or a mixture of product and slack into the product receiving volumes 18a, 18b (as shown in FIG. 1b) and opening the respective gates 12a, 12b of the hopper 10 (as shown in FIG. 1d). Similarly, the percentage of slack S that can be separated from the mixture can be affected by varying the configuration of each filter wall 24a, 24b and its holes 26, as well as the size and relative angles of the slack removal chambers 20 and the gates 12a, 12b. FIG. 1c shows an arrangement in which the majority of the slack S has been removed from the product P. Indeed, in preferred embodiments, 95% or more of the slack S is removed (e.g., measured by weight and / or volume) from a mixture of product P and slack S. However, in other examples, it may be sufficient to remove at least 15%, at least 25%, at least 50% or at least 75% of the slack by weight and / or volume from product P.

[0117] In a preferred embodiment of the method, a predetermined delay time can be provided between delivering the mixture of product P and slack S to the product receiving volumes 18a, 18b and thereafter moving the respective gates 12a, 12b to their open positions to deliver the contained product P. This time is typically in the range of 200 ms to 100 ms, more preferably in the range of 400 to 600 ms.

[0118] Alternatively, the weight of the hopper 10 and / or the contents of one or more of the product receiving volumes 18a, 18b may be monitored to determine when the hopper 10 has reached a steady state and / or when sufficient slack S has been removed from the mixture of product P and slack S. The hopper and / or the respective product receiving volume 18a, 18b is opened only when such a determination is made. This process may include obtaining a time series of weight measurements of the contents of the hopper, the first product receiving volume 18a and / or the second product receiving volume 18b. The time series may be continuous or periodic. The weight measurements may then be analyzed by a controller to determine when the weight of the contents has stabilized. For example, it may be deemed stable if the change in weight between two or more successive measurements is less than a predetermined weight value.

[0119] Once the slack S has been removed from the mixture of product P and slack S, the gates 12a, 12b of the hopper 10 are opened and the remaining product P is discharged or dispensed along with the slack. For example, the hopper 10 can feed the product P to a packaging machine, a further hopper, or further processing machinery (not shown).

[0120] The hopper 10 is shown in Figure 1d with the gates 12a, 12b open. Products P from the first product receiving volume 18a leave the hopper 10 along a first path indicated by arrow D1. Products P from the second product receiving volume 18b leave the hopper 10 along a second path indicated by arrow D2. This movement occurs under gravity. The first and second paths taken by products P from the opposing product receiving volumes 18a, 18b are substantially parallel, although this is not required.

[0121] The first and second gates 12a, 12b are then closed and the hopper returned to the configuration of FIG. 1a, and the process can be repeated with additional batches of product P. The slack S separated from the mixture of product P and slack S and retained within the inner chamber 22 of the slack remover 20 can be periodically or continuously recovered (i.e., removed). Recovery can be manual or automatic (e.g., using a vacuum pump connected to the inner chamber 22). As noted above, in some cases, the slack S may be recycled or reincorporated into the product process upstream of the hopper 10.

[0122] During the above process, the slack remover 20 remains stationary. As can be seen from the figures, the gates 12a, 12b are opened and closed while the slack remover remains in substantially the same position. The slack remover is unpowered and need not be connected to a motor or other actuator configured to provide movement. Nevertheless, preferably, the slack remover 20 is removably secured to the hopper so that it can be removed for emptying, cleaning or maintenance. Even if the slack remover is removably secured to the hopper and is substantially stationary during use, vibrations may be imparted to the slack remover 20 and the slack S therein as the gates 12a, 12b of the hopper 10 are opened and closed.

[0123] In the method described above with reference to Figures 1a-1d, the product receiving volumes 16a and 16b of the hopper 10 are filled and emptied simultaneously, the opposing sides of the hopper 10 are operated synchronously and the first and second gates 12a, 12b are opened and closed together, although this is not required.

[0124] Figures 2a to 2c show further method steps carried out using the hopper 10 described above with reference to Figures 1a to 1d, in which opposite sides of the hopper 10 are operated asynchronously (i.e., alternately).

[0125] 2a shows an arrangement in which both the first and second gates 12a, 12b are in a closed position. However, only the second product receiving volume 18b is provided with a mixture of product P and slack S. As mentioned above, in this arrangement, the slack tends to be separated from the mixture in the second product receiving volume 18b and pass through the second filter wall 24b and into the inner chamber 22 of the slack remover 20. This movement of the slack is indicated by the arrow R3.

[0126] Then, in a further step shown in Figure 2b, simultaneously: the second gate 12b is moved to its open position (as shown by arrow D3) so that the product in the second product receiving volume 18b is discharged along the second path mentioned above, and the mixture of product P and slack S is introduced into the first product receiving volume 18a.

[0127] The second gate 12c can then be closed while slack S is removed from the mixture in the first product receiving volume 18a. This arrangement is shown in Figure 2c. Arrow R4 shows how slack S from the first product receiving volume 18a enters the inner chamber 22 through hole 26 in the first filter wall 24a.

[0128] Thus, the configuration of the hopper 10 is a mirror image with respect to the initial configuration of Fig. 2c: in Fig. 2a the first product receiving volume 18a is empty and the second product receiving volume 18b contains a mixture of product P and slack, whereas in Fig. 2c the first product receiving volume 18a is filled with the mixture and the second product receiving volume 18b is empty.

[0129] The product P in the first product receiving volume 18a can then be dispensed by opening the first gate 12a while further mixture is introduced into the second product receiving volume 18b (a mirror image or reflection of the situation shown in Figure 2b). After closing the first gate 12a, the hopper 10 is returned to the position of Figure 2a and the method is repeated.

[0130] Thus, it is understood that the first and second gates 12a, 12b need not be operated together, but instead may alternately fill and empty different product receiving volumes 18a, 18b. This asynchronous process provides high speed processing. The delay required for slack to be separated from the mixture of product P and slack S in the product receiving areas 18a, 18b is ameliorated by independently operating opposite sides of the hopper 10.

[0131] In a further embodiment, the hopper 10 can be controlled to vary between the synchronous and asynchronous processes described above, for example, based on the weight of the products in the product receiving areas 18a, 18b.

[0132] A modification of the hopper 10 shown in Figures 1 and 2 will now be described with reference to Figure 3. Figure 3 shows a hopper 10' which shares all the features of the hopper 10 of Figures 1 and 2. Corresponding features are indicated with the reference numerals in the above notation.

[0133] In addition to the features of the original hopper 10, the hopper 10' of FIG. 3 includes an internal baffle 28 disposed within the internal chamber 22' of the slack removal body 20'. The internal baffle 28 is disposed between and separates the first filter wall 24a' and the second filter wall 24b' and is configured to prevent the passage of slack. Thus, the internal baffle 28 prevents or acts to prevent slack that enters the internal chamber 22' from the first product receiving volume 18a' through the first filter wall 24a' from immediately exiting the slack removal body 20' through the holes in the opposing second filter wall 24b'. This prevents the slack from being returned to the product path or surrounding machinery.

[0134] As shown, the internal baffle 28 extends along the centerline of the slack removal body 20', although this is not required. Additionally, a gap 28a exists between the internal baffle 28 and the bottom surface of the internal chamber 20' to allow slack at the bottom of the internal chamber 20' to intermingle. However, this feature is also not required. In some embodiments, the internal baffle may span the full height of the slack removal body, dividing its interior into two separate internal chambers for independent collection of slack.

[0135] More commonly, hoppers having a single internal chamber (as shown in the examples of Figures 1-3), while easier to empty and / or clean, are not required. A hopper may have two or more internal chambers, with a first filter wall separating a first product receiving volume from a first internal chamber and a second filter wall separating a second product receiving volume from another second internal chamber. In this way, the separate internal volumes collect slack from the separate product receiving volumes.

[0136] 3 further illustrates an arrangement of the hopper 10' with the second gate 12b' in an intermediate position between the open position O and the closed position C (shown by a dashed version of the gate). The intermediate position is closer to the closed position C than the open position, and is approximately 90-95% of the distance from the open position O to the closed position C.

[0137] In some methods of separating slack from a product mix, the closing of the first gate 12a' and / or the second gate 12b' of the hopper 10' has two separate (i.e., separate) closing steps: a first closing step in which the gates 12a', 12b' are moved from an open position to an intermediate position, and a second closing step in which the gates 12a', 12b' are moved from the intermediate position to a closed position. Between the two closing steps, the gates are substantially stationary and gate movement is paused. This two-step process is highly dynamic and can impart large vibrations to the slack remover 20' and its contents. This two-step gate closing process can be used in the manner described above with reference to Figures 1 and 2.

[0138] The hopper 10 shown in Figures 1 and 2 is of the "double-sided" type, having a pair of opposing gates 12a, 12b and a pair of opposing product receiving volumes 18a, 18b located on either side of a slack remover 20. In contrast, Figures 4a and 4b show a schematic cross-section of a hopper 30 which is also suitable for removing slack from a product and slack mixture, but which is of the "single-sided" type, having a single gate 32a and a single product receiving volume 38a. The reference numbers of features of the hopper 30 in Figures 4a and 4b which correspond to equivalent features of the hopper 10 shown in Figures 1 and 2 have been increased by 20 between the figures.

[0139] As can be seen, the single sided hopper 30 of Figure 4 has a gate 32a configured to rotate about a hinge 34a coupled to a stationary wall 36a. Figure 4a shows the hopper 30 with the gate 32a of the hopper 30 in a closed position, where product is held in the product receiving volume 38a of the hopper 30. Figure 4b shows the gate 32a of the hopper 30 in an open position, where product is being discharged from the hopper 30. It can be seen that the gate 32a has a hinged end coupled to the hinge 34a and an opposite free end 32a1 at a distal portion of the gate 32a furthest from the hinge 32a.

[0140] The hopper 30 has a slack remover 40 configured to separate and store slack introduced into or generated within the product receiving volume 38a of the hopper 30. Product or a mixture of product and slack may be introduced into the product receiving volume through the upward opening 37a. The slack remover 40 has an interior chamber 42 that is hollow and configured to receive slack, and a filter wall 44a designed to allow the passage of slack but prevent the passage of product. The filter wall 44a extends between the interior chamber 42 of the slack remover 40 and the product receiving volume 38a.

[0141] The filter wall 44a has a plurality of holes 46 sized to allow slack to enter the interior chamber 42. As such, a portion of the filter wall 44a is formed as a mesh, grill, grate, filter, gauze, sieve, or net.

[0142] Additionally, filter wall 44a includes a slot 48 configured to receive free end 32a1 of gate 32a of hopper 30 when gate 32a is in the closed position. This slot 48 extends entirely through filter wall 44a. Slot 48 has a width greater than the maximum dimension of a slack used in hopper 30 and a length that is preferably at least as large as the width of free end 32a1 of gate 32a. As can be seen, slot 48 is located in filter wall 44a at a location where gate 32a and filter wall 44a would intersect without slot 48.

[0143] As shown in FIG. 4a, in its closed position, the gate 32a is inclined (i.e., angled) toward the filter wall 44a so that its free end 32a1 enters the slot 48. Thus, when the gate 32a is in its closed position, slack in the product receiving volume 38a that is in contact with the inner surface of the gate 32a is likely to flow down the gate 32a by gravity and directly into the inner chamber 42 of the slack receiving body 40. Therefore, the slack can be particularly easily separated from the mixture of product and slack in the product receiving volume 38a. The gap formed between the boundary of the gate 32a and the slot 48 is smaller than the minimum dimension of the product used in the hopper 30. Therefore, when the gate 32a is closed, the product can be securely retained in the product receiving volume 38a of the hopper 30.

[0144] It will therefore be appreciated that the slots 48 shown in Figures 3a and 3b are illustrative of the holes provided through the filter wall of the slack remover discussed herein. These slots may be incorporated into the so-called "double-sided" hoppers shown in Figures 1 and 2. In further embodiments, the filter wall may only be provided with a slot, which is a single hole through the filter wall that allows slack to pass through to the interior chamber of the slack remover.

[0145] The hopper 30 shown in Figures 4a and 4b can be operated to remove slack from a product and slack mixture using a method similar to the example described above with reference to Figures 1 and 2.

[0146] When the gate 32a of the hopper 30 is in the closed position (as shown in FIG. 4a), a mixture of product and slack may be provided or introduced into the slack receiving volume 38a. The product is then retained in the product receiving volume 38a, and the slack tends to exit the product receiving volume 38a and enter the internal chamber 42 of the slack remover 40. In so doing, the slack passes through holes 46 and slots 48 that extend through the filter wall 44a of the slack remover 40. The product and remaining slack can then be discharged (i.e., dispensed) from the hopper 30 by moving the gate 32a to the open position. This provides a path for the product to exit the hopper by gravity. Finally, the gate 32a is moved to the closed position, closing the path for the product to exit the hopper 30, allowing the process to be repeated. In this manner, the slack remover 40 remains substantially stationary. In practice, preferably the slack remover is not activated but is removably secured to a stationary component (e.g., stationary wall 36a) of the hopper 30. The method and hopper 30 shown in Figures 4a and 4b may include any of the additional steps and features described above with reference to Figures 1 and 2.

[0147] Although not shown in the schematics of Figures 1 and 2, in many product and slack combinations, the slack will tend to fall faster due to gravity than the product. Thus, when a mixture of product and slack is introduced into the hopper 30 of Figures 4a and 4b, it will tend to reach the gate 32a before the product and will be quickly diverted through the slot 48 to the slack remover 40.

[0148] A further hopper 100 suitable for removing slack from a product and slack mixture is shown in Figures 5a to 5f. Again, this hopper 100 is particularly suitable for food products. Moreover, the hopper 100 can be operated to remove slack by the same method steps as described above with reference to Figures 1, 2 and 3.

[0149] Figures 5a and 5b show hopper 100 in isometric perspective views, Figures 5c and 5d show hopper 100 in side views from a position similar to the cross-sections of Figures 1 to 3, and Figures 5e and 5f show cross-sections along lines A-A and BB shown in Figures 5c and 5d.

[0150] The hopper 100 is of a substantially symmetrical double-sided structure and has two movable gates, a first gate 110 and a second gate 120. The movable gates 110, 120 are on opposite sides of a slack remover 130. The gates 110, 120 can be moved between respective closed and open positions. Figures 5a, 4c and 4e show the hopper 100 with both gates 110, 120 in their respective closed positions, while Figures 5b, 5d and 5f show the hopper 100 with the gates 110, 120 in their respective open positions. The first and second gates 110, 120 are configured to rotate about respective first and second hinges 111, 121. Each gate 110, 120 can be actuated by a motor, such as (for example) a Harmonic Drive®, a linear servo motor or a pneumatic actuator connected to a respective bracket 112, 122 on the exterior of the gate 110, 120.

[0151] The slack remover 130 is hollow and has an internal chamber 131 configured to receive and hold slack. Furthermore, the slack remover 130 has two opposing filter walls 132, 133. Each of the filter walls 132, 133 is configured to allow the passage of slack but prevent the passage of product. Thus, each filter wall 132, 133 is composed of a number of small circular holes 134 arranged in a regular pattern. The regular pattern of the holes 134 in the second filter wall 133 can be seen in Figures 5b, 5e and 5f. As in the previous embodiment, the holes 134 have dimensions larger than the typical dimensions of slack but smaller than the typical dimensions of the product. The preferred dimensions of the holes 134 in the plane of the filter walls (i.e. the diameter of the circular holes 134) are between 0.05 cm and 1 cm, preferably between 0.1 cm and 0.5 cm.

[0152] Additionally, the first and second filter walls 132, 133 each have a slot 135, and the hopper 100 is configured such that a free end of the first gate 110 enters the slot 135 in the first filter wall 132 when the first gate 110 is in its closed position, and a free end of the second gate 120 enters the slot 135 in the second filter wall 133 when the second gate 120 is in its closed position. Each slot 135 is wider than the free end of the respective gate 110, 120 and extends continuously along the free end of the respective gate 110, 120 when the gate 110, 120 is in its closed position. As can be seen, each slot 135 is disposed within each filter wall 132, 133 at a location where said filter wall 132, 133 and each gate 110, 120 would intersect if the slot 135 did not exist and / or if the length of the gate 110, 120 were greater.

[0153] When the first gate 110 is in its closed position (as shown in Figures 5a, 5c and 5e), a first product receiving volume is defined between the gate 110 and the first filter wall 132. The hopper 100 is configured such that product dispensed into this volume is retained while the first gate 110 is closed. Similarly, when the second gate 120 is in its closed position (as shown in Figures 5a, 5c and 5e), a second product receiving volume is defined between the gate 120 and the second filter wall 133.

[0154] The hopper 100 further comprises two chutes, a first chute 140 and a second chute 150, through which the product or a mixture of product and slack is introduced into the respective first and second product receiving volumes. The chutes 140, 150 are tubular with a rectangular cross section when viewed from above. The product received in each chute 140, 150 is directed into the corresponding product receiving volume when the respective gate 110, 120 is closed. Thus, the chutes 140, 150 define an opening into the corresponding product receiving volume. The chutes 140, 150 are arranged such that the mixture of product and slack is directed substantially perpendicularly towards the respective filter walls 132, 133. Thus, the average direction of the product and / or slack as it enters the hopper and contacts the respective filter walls 132, 133 is at an angle of more than 45 degrees with respect to the surface of the respective filter walls 132, 133. This allows an increased proportion of slack that can pass through the holes 134 in each filter wall 132,133.

[0155] When a mixture of product and slack is fed into one or both of the product receiving volumes of the hopper 100, the slack tends to move through the holes 134 and slots 135 in the corresponding filter walls 133, 134, thereby entering the internal chamber 131 within the slack remover 130. In this manner, the slack is separated from the product remaining in the product receiving volume, as the product cannot pass through the filter walls 133, 134. The product with the reduced slack level can then be discharged by opening the corresponding gates 110, 120. During this slack removal process and the movement of the gates 110, 120, the slack remover 130 remains substantially stationary.

[0156] Slack that enters the interior chamber 131 of the slack remover 130 can be continuously or periodically removed through a circular port 136. Port 136 is an opening into the interior chamber 131 of the slack remover 130 and is located in a sidewall 137 of the slack remover 130. For example, a vacuum pump can be connected (e.g., via a hose or tube) to port 136 to empty the hopper of slack. In further embodiments, other openings for this purpose can be provided elsewhere in the slack remover 130.

[0157] As can be most easily seen in Figures 5e and 5f, the port 136 is located at the bottom surface 131a of the internal chamber 131 (i.e., where the sidewall 137 of the slack remover abuts the bottom surface 131a of the internal chamber 131). Furthermore, the bottom surface 131a of the internal chamber 131 is angled relative to the horizontal in use, sloping towards the port 136. This angle relative to the horizontal is represented by the symbol θ in Figures 5e and 5f. Thus, the port 136 (i.e., the opening) is at the lowest point of the internal chamber 131, at a point where slack tends to accumulate due to gravity during use. Furthermore, activation of a vacuum pump (not shown) connected to the port 136 tends to pull slack from the bottom surface 131a down towards the port 136.

[0158] Furthermore, the slack remover 130 has a number of exterior openings 138 extending between its interior chamber 131 and the exterior of the hopper 100 when the gates 110, 120 are in both their open and closed positions. In fact, as can be seen, the slack remover 130 is wider than each of the first and second gates 110, 120. The exterior openings 138 extend through exterior walls 138 of the slack remover that protrude beyond the boundaries of the gates 110, 120. These exterior walls 138 are continuous with and flush with the filter walls 133, 134 of the slack remover 130, respectively. Slack in the air surrounding the hopper 100 can be collected in the interior chamber 131 of the slack remover 130 through the exterior openings 138. This is particularly successful when suction from a vacuum pump is applied to the interior chamber 131 through the port 136.

[0159] The slack remover 130 is removably connected (i.e., secured) to the rest of the hopper 100 by two clips 160. The clips 160 allow the slack remover 130 to be quickly removed and / or replaced with a new one when necessary for cleaning and / or maintenance. The clips 160 are formed of a resilient material and are biased against each other to hold the slack remover 130 in place during use. To remove and replace the slack remover 130, the clips 160 can be manually separated. Thus, the slack remover 130 can be separated or removed from the hopper 100 by hand and without the need for additional tools (i.e., the clips 160 form a quick release mechanism). The clips themselves are coupled to the remaining components of the hopper by screws or bolts 160a. In an alternative embodiment, the clips 160 may be rigid such that they cannot be manually separated. In such instances, the slack eliminator 130 can be removed by loosening (e.g., with a screwdriver) the screw or bolt 160a between each clip 130 and the slack eliminator 130. In further preferred embodiments, each screw or bolt 160a having a conventional head as shown can be replaced with a screw, bolt or nut having a lever extending from its head at an angle relative to the longitudinal axis of the screw, bolt or nut. In these embodiments, the screw, bolt or nut can be manually tightened or loosened using the lever without the need for additional tools.

[0160] Each gate 110, 120 of the hopper 100 has a respective main wall 113, 123 that extends coplanar with the hinge 111, 121 about which the respective gate 110, 120 rotates. Additionally, each gate 110, 120 has two side walls 114, 124 arranged to project perpendicularly from the respective main wall 113, 123 towards the slack remover 130. When each gate 110, 120 is in its respective closed position, the side walls 114, 124 contact the slack remover 130. Thus, the act of moving a gate 110, 120 to its closed position causes that gate's side wall 114, 124 to contact the slack remover 130, thereby transmitting vibrations to the slack remover 130 and its contents (i.e., any slack that has been collected). These vibrations act to continue the flow of slack along the bottom surface 131a of the internal chamber 131 towards the port 136. The port 136 allows for the removal or collection of slack from the slack removal body 130.

[0161] It should be noted that the free end of each gate 110, 120, i.e., the distal end of the main wall of the gate 110, 120, does not contact the slack remover 130 as it instead fits into a slot 135 in the filter wall.

[0162] The hopper 100 further includes a fixing bracket 170 that allows it to be supported and / or connected to surrounding equipment. For example, the hopper 100 can be bolted or screwed to a support structure via the fixing bracket 170, as desired. The hinges 111, 121 and clip 160 are coupled to the fixing bracket 170 by screws and / or bolts.

[0163] The hopper 100 is preferably constructed of folded stainless steel, although other suitable materials may be used.

[0164] Figure 6 shows diagrammatically a system 100 incorporating the hopper 100 shown in Figure 5. The system further comprises a combination weigher 200 arranged upstream of the hopper 30. An example of a suitable combination weigher is the RV Series Multi-Head Weigher sold by Ishida Europe Limited, 11 Kettle's Wood Drive, Woodgate Business Park, Birmingham B323DB.

[0165] In general, the combination weighing machine has a series of weighing hoppers 210, only two of which are shown in FIG. 6, arranged in a circle around a central axis. Each weighing hopper is fed by a feeding device, such as a product dispersion table, and receives a certain amount of product. The weight of the products in each hopper is continuously monitored, and the combination weighing machine selects any two or more hoppers whose total weight meets a criterion for the weight of the batch of products to be formed, dispenses products from those hoppers, and combines the products into a single batch of products having a desired weight. In this embodiment, the combination weighing machine 200 has a funnel 220 that surrounds all the weighing hoppers 210, and combines the products dispensed by any two or more weighing hoppers 210 and deposits them in the slack separating hopper 100. It should be noted that each weighing hopper 210 can also be formed as a slack separating hopper with a slack remover therein according to the present invention, but this is not required.

[0166] Only part of a packaging machine 300 is shown diagrammatically in Figure 6. An example of a packaging machine suitable for use in the present system is the Astro bag making machine sold by Ishida Europe Limited, 11 Kettlewood Drive, Woodgate Business Park, Birmingham B323DB.

[0167] The packaging machine 300 includes a former 310 that forms a feed film into a cylinder that is sealed at intervals by a sealer (not shown) to form individual bags. The former 310 has an inner forming tube 311 and an outer forming collar 312 that together form the feed film into a cylinder. The packaging machine also has a funnel 320 connected to the top opening of the inner forming tube 311 to feed product into the bag being formed.

[0168] In the present system 1000, the hopper 100 receives the product from the weigher 200, separates the slack, and then dispenses a batch of product along a first path where the product falls vertically under gravity when the hopper opens and enters the funnel 320 of the packaging machine 300 to be received in a package, i.e., a bag, which is formed by the packaging machine. The product is typically dispensed by the hopper 30 as a bottom seal of the bag is made, and as the product enters the bag, a top seal is made to seal the bag. This top seal forms the bottom seal of the next bag so that the process can be repeated.

[0169] The timing of when the hopper 100 opens to dispense products to the packaging machine is typically controlled by a system controller (not shown) which together controls the weigher 200, hopper 100 and packaging machine 300 of the system 1000. Typically, the system operates a full cycle in 100-1000 ms, most commonly 400-500 ms. That is, batches of products are dispensed by the hopper 100 at regular intervals of approximately 400-500 ms to match the production rate of packaging by the packaging machine 300. Therefore, hoppers used in this manner are typically referred to as timing hoppers.

[0170] 6 shows the hopper 100 integrated between the weigher 200 and the packaging machine 300, it will be appreciated that the hopper 100 is suitable for use anywhere along the production of the product and slack mix. For example, as previously discussed, the hopper can be integrated into the weigher 200 or can be part of the feed to the weigher 200.

[0171] The system preferably includes a vacuum pump (not shown) configured to remove slack from the slack removal body of the hopper 100. The vacuum pump may be solely connected to the hopper 100 (i.e., the vacuum pump is connected to a single piece of equipment) or the vacuum pump may be a central pump configured to be connected to multiple pieces of equipment within the system 1000 and / or the larger packaging facility.

[0172] In system 1000, all products dispensed from hopper 100 are directed to the same packaging machine, however, this is not required and in other examples products discharged from different gates of the hopper may be directed to different discharge paths or different downstream machines.

[0173] Figure 7A is a perspective view showing the exterior of a slack remover 430 of a further hopper 400, while Figure 7b is a cutaway perspective view showing the interior of this slack remover 430. The hopper 400 is similar to the embodiment described above with reference to Figures 5a to 5f. Corresponding features that may have corresponding functions, structures and / or advantages are numbered in increments of 300 in these figures.

[0174] The slack remover 430 has an interior chamber 431 configured to receive and hold slack. The interior chamber 431 is defined between two opposing filter walls 432, 433. The filter walls 432, 433 are separated by a side wall 437 of the slack remover 430. The filter walls 432, 433 are configured to allow the passage of slack but prevent the passage of product.

[0175] As discussed above with reference to Figures 1-5, the hopper 400 has movable gates located on opposite sides of the slack remover 430. The movable gates are movable between an open position, in which the contents of the hopper are dispensed, and a closed position, in which product and slack are retained within the product receiving volume. A single movable gate 420 is shown in Figure 7a so that the features of the slack remover 430 can be observed. The movable gate 420 is shown in a closed position in Figures 7a and 7b. Each gate 420 may be actuated by a motor, such as a Harmonic Drive® (for example), a linear servo motor, or a pneumatic actuator connected to a respective bracket 422 on the exterior surface of the gate 420.

[0176] The mixture of product and slack may be fed into respective product receiving volumes defined between each gate and the slack remover 430. The hopper has chutes 440, 450 positioned to direct the mixture into the respective product receiving volumes.

[0177] Slack within the product receiving volume is able to pass through corresponding filter walls 432, 433 of the slack remover 430, as described with reference to the previous figures. As a result, the hopper 400 is configured to dispense product with less slack than was present in the mixture initially received by the hopper 400.

[0178] The filter walls 432, 433 are multi-layered. As can be seen, each filter wall 432, 433 is formed from two layers of sheet material, 432a, 432a and 433a, 433b. Each layer 432a, 432a, 433a, 433b is preferably formed from stainless steel sheet, although other materials are suitable. In a preferred embodiment, the layers 432a, 432a and 433a, 433b and other components of the hopper 400 are laser cut and then folded to the appropriate shape.

[0179] As best seen in the internal view of Fig. 7b, the two layers of each filter wall 432, 433 are adjacent and in contact with each other. The two layers 432a, 432b and 433a, 433b are preferably fixed to each other by welding, rivets, bolts or other options. Welding is particularly preferred as it requires fewer parts. The outer layer 432b, 433b of each filter wall 432, 433 is formed in continuity with the respective chute 440, 450. However, this is not required.

[0180] The inner layer 432a, 433a and outer layer 432b, 433b of each filter wall 432, 433 have a plurality of holes extending through the respective layer and through the filter wall 432, 433 as a whole. These holes are best seen in Figure 7b.

[0181] First, each inner layer 432a, 433a has a lower slot 435 configured to receive the free lower edge of the corresponding gate when the gate is in the closed position. The lower slot 435 is further sized to allow slack to pass through but not product. When the gate 420 is closed, slack tends to flow by gravity down the inner surface of the gate 420 and through the lower slot 435 into the inner chamber 431 of the slack receiver 430.

[0182] Each inner layer 432a, 433a has projections 435a, also called teeth, extending from the long side of the lower slot 435. The projections 435a extend into and across the opening of the lower slot 435. Specifically, the projections 435a extend downwardly across the slot from the upper edge of the slot. The length of the projections 435a is approximately half the width of the lower slot 430. For example, the length of the projections can be 25-75% or 40-60% of the width of the lower slot 435. The projections 435a help to prevent large objects from passing through the lower slot 435 into the inner chamber 431. Thus, during use, the projections 435a help to prevent product from entering the inner chamber 431 while allowing the passage of slack. The projections 435a are particularly valuable when the product has a wide range of dimensions and / or is relatively flat with one dimension smaller than the other. The free end of the corresponding gate 420 can enter the slot 435 below the protrusion 435a.

[0183] As shown in Figures 7a and 7b, the protrusion 435a extends in the same plane as its inner layers 432a, 433a. However, in further embodiments, the protrusion 435a may be bent a small amount into the outer chamber. For example, the protrusion may be bent at its base or along its length between 0 and 40 degrees relative to the plane of the filter walls 432, 433. In this way, the protrusion 435a extends into the inner chamber 430. This makes it possible to avoid a collision between the free end of the corresponding gate 420 and the protrusion 435a when the gate is closed.

[0184] The inner layers 432a, 433a of the filter walls 432, 433 may each further include two side slots 439 configured to receive the sides of the respective gate when the gate is in the closed position. This arrangement helps ensure that the gate closes tightly against the interior chamber 431 of the hopper 400 and prevents product and / or slack from being accidentally discharged from the hopper 400 when the gate is closed.

[0185] The outer layers 432b, 433b of the inner chamber 431 have an array of circular holes 434 for filtering slack from the product. Each hole 434 is relatively small and sized to allow slack to pass but not product to pass through. Each hole 434 has a diameter smaller than the smallest dimension of the product. If the slack is solid, the holes 434 have a diameter larger than the largest dimension of the slack. An array of circular holes 434 is easily formed. However, in further embodiments, the holes 434 can have alternative shapes and / or arrangements. For example, the holes 434 can be formed in substantially any shape (e.g., oval, square, triangular) and arranged in substantially any pattern, including repeating or random arrangements. Additionally or alternatively, the outer layers 432b, 433b can be comprised of an array of meshes, grilles, lattices, gauze, sieves, nets, or slots in place of the holes 434.

[0186] The inner layers 432a, 433a of the inner chamber 431 further include a large central hole 480, as seen in FIG. 7b. The central hole 480 overlaps and extends across the array of circular holes 434 in the outer layers 432b, 433b, which filter the slack and product. Thus, the periphery of each large central hole 480 extends around and surrounds the corresponding circular hole 434 in the outer layers 432b, 433b. Thus, it can be seen that the circular holes 434 extend through both layers of the filter walls 432, 433. Slack passing through the circular holes 434 enters the inner chamber 431 of the slack remover 430.

[0187] The inner chamber 431 further has an angled bottom surface 431a that, in use, is angled with respect to the horizontal axis and slopes towards the port 436 of the hopper 430. The port 436 is a large hole through which slack may be removed or collected from the inner chamber 431. In use, a vacuum pump may be connected to the port 436. Slack that passes through the filter walls 432, 433 and accumulates in the inner chamber 431 tends to slide down the sloped bottom surface 431a due to gravity and / or the action of a vacuum pump, if present. In this manner, the angled bottom surface 431a is configured to guide or encourage the slack towards the port 436.

[0188] The hopper 400 is fixed in place by a wing bolt 471 which secures the hopper to a fixing bracket 472. Many other fixing methods are possible.

[0189] It will also be appreciated that in the example of a hopper having multiple filter walls, a variety of different holes are provided in the different layers. For example, one or both of the layers 432a, 433a and 432b, 433b of each filter wall 432, 433 of the hopper shown in FIG. 7 can be provided with holes arranged to filter slack from the product. For example, in some embodiments, a set of holes configured to allow slack but not product can be formed in each inner layer 432a, 433a, and larger holes extending across these holes can be formed in each outer layer 432b, 433b of the filter walls 432, 433. Similarly, both layers 432a, 433a and 432b, 433b can be provided with overlapping sets of small holes arranged to filter slack from the product.

[0190] The hopper 400 of Figures 7a and 7b can be incorporated into the system 1000 shown in Figure 6. Thus, the hopper 400 can be a timing hopper configured to receive a mixture of product and slack from a computer-controlled weigher or other feeding device. Alternatively, the hopper 400 can be used as a different hopper within the computer-controlled weigher, such as a pool hopper, a weigh hopper, a booster hopper, an output hopper or a discharge hopper.

[0191] Moreover, the features of this hopper 400 can be combined with any of the features of the particular hopper described above in relation to the previous figures. For example, the bottom slot 135 of the hopper 100 of Figures 5a-5f can be provided with the teeth or projections 435a and / or its side slots 439 of the hopper 400 of Figures 7a and 7b. Similarly, the hopper 400 of Figures 7a and 7b can be provided with the external openings 138 described with reference to the hopper 100 shown in Figures 5a-5f. Similarly, the hopper 400 of Figures 7a or 7b can have a filter wall with a single layer, while the hopper 100 of Figures 5a-5f can have a filter wall with multiple layers.

[0192] The present invention provides improved products to end users, particularly improved food products. The percentage of slack that ultimately reaches the customer is reduced by the hopper, system and method described above.

[0193] Moreover, it will be appreciated that a hopper according to the present invention, such as hopper 100 shown in Figures 5 and 6, or hopper 400 shown in Figure 7, can be easily retrofitted into existing systems to replace an equivalent hopper that does not have the ability to remove slack. Thus, the present invention provides an opportunity to upgrade existing systems.

Claims

1. A hopper for separating slack from a mixture of product and slack, a first gate movable between respective open and closed positions; a slack remover; Equipped with the first gate and the slack remover are positioned to define a first product receiving volume therebetween when the first gate is in its closed position; the slack remover has a first internal chamber for receiving slack and a first filter wall separating the first internal chamber from the first product receiving volume, the first filter wall configured to block the passage of product but allow the passage of slack; The first gate is providing a first path for product to exit the first product receiving volume when the first gate is in its open position; when the first gate is in its closed position, the first path is closed and product is retained in the first product receiving volume; It is configured to the slack remover is configured to remain substantially stationary as the first gate is moved between its open and closed positions. Hopper.

2. The slack remover is removably fixed to other components of the hopper.

2. The hopper of claim 1.

3. The first internal chamber of the slack remover has an opening for removing slack.

3. A hopper according to claim 1 or 2.

4. the opening of the first internal chamber is configured to be connected to a vacuum pump positioned to remove slack from the first internal chamber.

4. The hopper of claim 3.

5. The opening is provided in a bottom surface of the first internal chamber.

4. The hopper of claim 3.

6. The bottom surface of the first internal chamber is inclined toward the opening so that gravity can easily move slack along the first internal chamber toward the opening.

4. The hopper of claim 3.

7. the first filter wall has one or more holes, each hole sized to allow the passage of slack but prevent the passage of product; 2. The hopper of claim 1.

8. the minimum dimension of each hole in the plane of the filter wall is 0.05 cm to 1 cm, preferably 0.1 cm to 0.5 cm; 8. The hopper of claim 7.

9. the first filter wall comprises a filter, mesh, grate, grill, gauze, sieve, and / or net; 9. A hopper according to claim 7 or 8.

10. the first filter wall has a slot, the slot being sized to allow passage of slack but prevent passage of product; When the first gate is in its closed position, the first gate is positioned so that a free end of the first gate is adjacent to and / or enters the slot, and an inner surface of the first gate is inclined toward the slot so that slack tends to move along the first gate toward the slot due to gravity.

3. A hopper according to claim 1 or 2.

11. the slack remover has one or more exterior holes extending between the first interior chamber and the exterior of the hopper when the first gate is in its open position and its closed position, respectively; The external holes are sized to allow the passage of slack but prevent the passage of product, so that slack in the air outside the hopper can enter the slack remover through the external holes.

3. A hopper according to claim 1 or 2.

12. The slack remover is configured so that vibrations caused by opening and / or closing of the first gate are transmitted to the slack remover and the contents of the slack remover.

3. A hopper according to claim 1 or 2.

13. the first gate has sidewalls positioned on either side of the first product receiving volume when the first gate is in its closed position, the sidewalls of the first gate configured to contact the slack remover when the first gate is in its closed position.

3. A hopper according to claim 1 or 2.

14. The hopper is a hopper used in a computer-controlled weighing machine.

3. A hopper according to claim 1 or 2.

15. The hopper is a timing hopper, a weighing hopper, a pool hopper, a booster hopper, an output hopper, or a discharge hopper.

3. A hopper according to claim 1 or 2.

16. The hopper is a second gate movable between respective open and closed positions; the second gate and the slack remover are positioned to define a second product receiving volume therebetween when the second gate is in its closed position; The second gate is providing a second path for product to exit the second product receiving volume when the second gate is in its open position; When the second gate is in its closed position, the second path is closed and product is retained in the second product receiving volume.

3. A hopper according to claim 1 or 2.

17. the first gate and the second gate are opposed to each other, and the slack remover is disposed between the opposed first gate and the opposed second gate; the slack remover has a second internal chamber for receiving slack and a second filter wall separating the second internal chamber from the second product receiving volume, the second filter wall configured to block the passage of product but allow the passage of slack; 17. The hopper of claim 16.

18. The first internal chamber and the second internal chamber of the slack remover are the same chamber.

18. The hopper of claim 17.

19. One or more hoppers according to claim 1; computer-controlled weighing and / or packaging machines; A system comprising:

20. The computer-controlled weighing machine is a combination weighing machine, a linear weighing machine, a cup filling machine or a volumetric filling machine.

20. The system of claim 19.

21. The packaging machine is a bag making machine, a vertical fill film seal (VFFS) machine, a boxing machine, a cartonizer or a canning machine; 21. A system according to claim 19 or 20.

22. 20. A method of separating slack from a mixture of product and slack using a hopper according to claim 1 or a system according to claim 19, comprising the steps of: (a) feeding a mixture of product and slack into a first product receiving volume of a hopper when the first gate is in its closed position, such that product is retained within the first product receiving volume and at least some slack from the mixture passes through the first filter wall and into the first internal chamber of the slack remover; (b) moving the first gate of the hopper to its open position so that the remaining contents of the first product receiving volume exit the hopper; A method for providing

23. (c) moving the first gates to their respective closed positions; The method includes repeating steps (a) through (c).

23. The method of claim 22.

24. The step (c) a first closing step of moving the first gate to an intermediate position between its open position and its closed position; followed by a subsequent second closing step of moving the first gate from the intermediate position to its closed position; The method includes two separate closing steps:

24. The method of claim 23.

25. The steps (a) and (b) are performed at least 100 ms apart, preferably at least 200 ms apart, and more preferably at least 400 ms apart.

23. The method of claim 22.

26. Following step (a), (i) obtaining a time series of weight measurements of the contents of the hopper and / or the first product receiving volume; (ii) determining that the weight of the contents has stabilized based on the weight measurements; Further provided with and (c) is performed only after the determination is made.

23. The method of claim 22.

27. (d) the slack remover further comprises a step of collecting the received slack.

23. The method of claim 22.

28. The method comprises: a hopper including a second gate movable between respective open and closed positions, the second gate and the slack remover are positioned to define a second product receiving volume therebetween when the second gate is in its closed position; The second gate is providing a second path for product to exit the second product receiving volume when the second gate is in its open position; When the second gate is in its closed position, the second path is closed and product is retained in the second product receiving volume. This is done using a hopper, (e) feeding a mixture of product and slack into the second product receiving volume of the hopper when the second gate is in its closed position, such that product is retained within the second product receiving volume and at least some slack from the mixture passes through a second filter wall into a second internal chamber of the slack remover; (f) moving the second gate of the hopper to its open position so that the remaining contents of the second product receiving volume exit the hopper; Further provided with Steps (b) and (f) may be performed separately or simultaneously; 23. The method of claim 22.

29. In step (b) or step (f), the product discharged from the hopper is transferred to a package and the package is sealed.

23. The method of claim 22.

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